#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve()
{
    int n;
    cin>>n;
    cout<<"a_";
    for(int i=3;i<=n;i++)cout<<'a';
}
signed main()
{
    //ios::sync_with_stdio(false);
    //cin.tie(nullptr);
    int T=1;
    //cin>>T;
    while(T--)
    {
       solve();
    }
    return 0;
}